|Date:||30th September 2023|
|Conditions:||calm to moderate winds, 32C Mostly sunny|
|Members:||GK, PK and Paul K|
Three days before departure I decided that I will need to add a reinforcing ring around the top of the payload bay in order to minimize the chance of a zipper. I just used an off cut from the payload bay tube and glued that on with epoxy. It is a little ugly and less aero dynamic but if it meant all the difference between getting a cert or not, it was worth it.
We also replaced the rubber bands in the deployment mechanism with fresh ones. If you leave the rubber bands stretched for too long they will deteriorate a lot faster and then can fail.
We also drilled new access holes in the nosecone which made it a lot easier to get the rocket turned on while it was on the pad.
This week we travelled to Mullaley to fly our L2 rocket. The weather looked beautiful in the morning with very little wind and blue skies all around. Because it was going to be a hot day and the fact there were some dry left over stalks from the previous crop on the ground, we were going to need to take some of it back. A sparky motor of this size can throw burning bits of titanium quite a ways. I wanted to give a big shout-out to a couple of the volunteers from Newcastle University that helped raking this stuff back.
Prep was pretty straight forward and Tim ended up inspecting the rocket as he was also the Tripoli prefect that was going to supervise this flight.
We turned on all the cameras and retreated back to the flight line. The motor took it's time to get up to pressure, but once it lit it had a nice lift-off. The rocket flew nice and straight and from the video we could see that it only did one roll on the way to apogee. As it passed through apogee, I was waiting to see the parachute, and for a couple of seconds there I didn't see it and I am thinking ...oh Sh*t.... but the parachute did open, it just took it a couple of seconds to fully unfurl after apogee.
We watched the rocket descend slowly and proceed to start drifting over our heads. By now the wind had picked up a little and so Paul and I started walking in the direction. It was heading straight over the farm behind the flight line. We had made the decision to simplify everything on this cert flight and so we just did the single deployment at apogee of the main chute knowing that we would have to potentially walk a lot further. It turns out the rocket drifted about 600m from the launch site.
As Paul and I followed it, we saw that it was coming down right in the middle of the trees on the farm. Paul got to it first and I could see that the rocket was hanging a few meters above him. Oh well, we've been in trees before, but as I got closer I noticed that the rocket wasn't in the trees, but hanging on the one power line on the property. The chances of that happening are pretty slim, but here we were. There is no way we were going to attempt to retrieve it ourselves as that is really asking for trouble. The shock cord was also hanging across both power lines. And so I walked back to the flight line to let the RSO know. As it turns out he had his connections and called the power company right away. Thanks to Israel and Melanie for their help in the recovery of the rocket, it was much appreciated.
The Tripoli cert rules state that if the rocket can be inspected in place and can be assessed that it could fly again then you can pass the L2 cert. So I went back and grabbed Tim and took him over the where the rocket was hanging. By the time we got there one of the guys from the power company had already arrived, and a second guy also just showed up as we did. So Tim was able to inspect it, and I asked the power guys to cut through the shock cord rather than the parachute shroud lines. They just had a couple of long telescopic fiberglass poles with a blade on the end and a couple of strokes later the parachute and the rocket were set free. I tried catching the rocket but missed so the rocket hit tail first but was fine. It was lucky the power guy was wearing a hard hat because the nosecone as it came down bounced off it. It was all good though and we had a good chat to the guys afterwards. They may even come out to watch the rockets next time with their kids. I guess they don't often get called out that a rocket is hanging in the power lines.
We recovered the rocket completely undamaged with the altimeter still beeping. So we ended up passing our L2 which we were really happy about. By then the wind had picked up even more, and so we decided not to fly any other rocket on the day. We were all pretty tired and Paul had pulled his back in the morning in the hotel so he wasn't up to it either. This is the first time we've gone to Mullaley and launched only one rocket, but it was worth it and we achieved our primary goal.
Here are some plots from the altimeter.
The data again showed a few spikes even though the altimeter was quite shielded from the sun, and you could see that the rocket caught a couple of thermals where the descent rate had slowed down.